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Version: 3.2

Expand your AKS cluster's storage pool size with disks managed by Portworx

If you're running on the cloud, consider automation into your decision for which pool resize approach you use. The pxctl service pool expand command allows you to perform resize operations without manually adding new drives or increasing drive capacity on your cluster.

When you enter the pxctl service pool expand command, Portworx uses your cloud provider's API to create new drives and attach them or to expand the existing drives with no further input from you.

You can control the pool expand operation by specifying which operation you want to use: resize-drive or add-drive, or you can specify auto to let Portworx determine the best way to resize your storage pools based on your cloud provider.

By default, each pool can have a maximum of 6 drives. If required, you can use the runtime option limit_drives_per_pool to change this value.

The maximum number of drives for the Azure platform, including boot drives, Portworx cloud drives, and any other drives, is 8.

Automatically expand a cloud-based pool​

  1. Run the following command to find the UUID for a pool:

    pxctl service pool show
    PX drive configuration:
    Pool ID: 0
            UUID:  xxxxxxxx-xxxx-xxxx-xxxx-aef346e61d89
            IO Priority:  HIGH
            Labels:  iopriority=HIGH,medium=STORAGE_MEDIUM_SSD
            Size: 384 GiB
            Status: Online
            Has metadata:  Yes
            Balanced:  Yes
            Drives:
            1: /dev/sde, Total size 128 GiB, Online
            2: /dev/sdf, Total size 128 GiB, Online
            3: /dev/sdg, Total size 128 GiB, Online
            Cache Drives:
            No Cache drives found in this pool
    Journal Device:
            1: /dev/sdc1, STORAGE_MEDIUM_SSD
    PX drive configuration:
    Pool ID: 0
            UUID:  46f7e68b-3892-xxxx-xxxx-xxxxxxxxxxxx
            IO Priority:  HIGH
            Labels:  iopriority=HIGH,medium=STORAGE_MEDIUM_SSD
            Size: 384 GiB
            Status: Online
            Has metadata:  Yes
            Balanced:  Yes
            Drives:
            1: /dev/sde, Total size 128 GiB, Online
            2: /dev/sdf, Total size 128 GiB, Online
            3: /dev/sdg, Total size 128 GiB, Online
            Cache Drives:
            No Cache drives found in this pool
    Journal Device:
            1: /dev/sdc1, STORAGE_MEDIUM_SSD

  2. Expand a cloud-based pool by entering the pxctl service pool expand command with the following options:

    • The --operation option to specify the desired operation
    • The --size option to set the minimum new size of the pool in GiB
    • The --uid option to provide the ID of the pool you want to resize
    pxctl service pool expand --operation auto --size 1000 --uid <pool-UUID>

    For example:

    pxctl service pool expand --operation auto --size 1000 --uid xxxxxxxx-xxxx-xxxx-xxxx-aef346e61d89

    For example:

    pxctl service pool expand --operation auto --size 1000 --uid 46f7e68b-3892-xxxx-xxxx-xxxxxxxxxxxx

  3. Once you submit the command, Portworx will expand the storage pool in the background. You can list the storage pools periodically to check if they have finished expansion.

    pxctl cluster provision-status

  4. When invoked on the Portworx node where the storage pool resides, the following command provides detailed information about the status of the pool expand process.

    pxctl service pool show

Resize or add a new drive to a cloud-based pool​

The auto operation automatically expands your pool capacity by increasing the pool size or adding the new drives to it. To perform a specific operation, replace auto with add-drive or resize-drive:

pxctl service pool expand --operation add-drive --uid <pool-ID> --size <new-storage-pool-size-in-GiB>

The auto operation automatically expands your pool capacity by increasing the pool size or adding the new drives to it. To perform a specific operation, replace auto with resize-drive or add-drive:

pxctl service pool expand --operation resize-drive --uid <pool-ID> --size <new-storage-pool-size-in-GiB>

Disk expansion with PremiumV2_LRS and UltraSSD_LRS disk types​

When using PremiumV2_LRS or UltraSSD_LRS disk types, a dedicated metadata device partition must be configured on the storage pool. This configuration is required to support disk expansion operations and to ensure metadata is preserved independently of the data pool.

To avoid losing metadata during the disk expansion process of PremiumV2_LRS and UltraSSD_LRS disk types, ensure the following conditions are met:

  • A dedicated metadata device must be available on the node.
  • The metadata device must be separate from the data drives used in the pool.
  • Each data pool must report Has metadata: No to confirm that metadata is not stored within the pool's data devices.

The following example shows a correctly configured storage pool with a dedicated metadata device:

[root@aks-nodepool1-3xx24542-vmss000001 /]# pxctl sv pool show
PX drive configuration:
Pool ID: 0
	Type:  Default
	UUID:  101103aa-1xxd-45c1-8dcc-059ee039fxxx
	IO Priority:  MEDIUM
	Labels:  kubernetes.azure.com/xxxxxx/xxxxxxx
	Size: 147 GiB
	Status: Online
	Has metadata:  No                        # Indicates metadata is stored separately
	Drives:
	1: /dev/sdf2, Total size 147 GiB, Online
	Cache Drives:
	No Cache drives found in this pool
Journal Device:
	1: /dev/sdf1, STORAGE_MEDIUM_SSD
Metadata Device:
	1: /dev/sde, STORAGE_MEDIUM_SSD          # Dedicated metadata device

In this configuration:

  • The Metadata Device is listed separately (/dev/sde).
  • The Has metadata field is set to No, confirming that metadata is not stored on the main data drives.

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